Usage
Bromocriptine is prescribed for various medical conditions, including:
- Hyperprolactinemia: High levels of prolactin in the blood.
- Acromegaly: Excess growth hormone production.
- Parkinson’s Disease: A neurodegenerative disorder affecting movement.
- Type 2 Diabetes: Sometimes used off-label.
- Neuroleptic Malignant Syndrome: A rare but serious reaction to antipsychotic medications.
- Suppression of postpartum lactation (for medical reasons): When breastfeeding is not advisable.
Pharmacological Classification: Dopamine agonist.
Mechanism of Action: Bromocriptine mimics the action of dopamine, a neurotransmitter, in the brain. It primarily activates dopamine D2 receptors, inhibiting prolactin secretion and improving motor control in Parkinson’s disease.
Alternate Names
- International Nonproprietary Name (INN): Bromocriptine
- Brand Names: Parlodel, Cycloset (for type 2 diabetes)
How It Works
Pharmacodynamics: Bromocriptine’s primary effect is dopamine receptor agonism, particularly at D2 receptors. This leads to:
- Inhibition of Prolactin Release: Reduces prolactin levels, treating hyperprolactinemia-related conditions.
- Improved Motor Control: Restores dopamine balance in the brain, alleviating Parkinsonian symptoms.
- Blood Sugar Regulation: May improve insulin sensitivity and glucose control (mechanism not fully understood).
Pharmacokinetics:
- Absorption: Well-absorbed orally, enhanced when taken with food.
- Metabolism: Extensively metabolized in the liver, primarily by CYP3A4.
- Elimination: Primarily excreted in bile and feces; a small portion is eliminated renally.
Mode of Action: Bromocriptine binds to and activates dopamine D2 receptors, leading to downstream effects such as inhibition of prolactin release and modulation of neuronal activity in the basal ganglia (relevant to Parkinson’s disease).
Receptor Binding: Primarily binds to dopamine D2 receptors.
Elimination Pathways: Hepatic metabolism (CYP3A4) followed by biliary excretion.
Dosage
Standard Dosage
Adults:
- Starting Dose: Typically 1.25 mg to 2.5 mg once daily with food at bedtime.
- Titration: The dose can be gradually increased every 2–7 days based on the patient’s response and tolerance.
- Maintenance Dose: Varies depending on the condition being treated, typically ranging from 2.5 mg to 30 mg per day, taken in divided doses with meals.
- Maximum Dose: Usually not more than 100 mg/day (lower for certain conditions, consult specific guidelines).
Children (7-17 years):
- Prolactinomas: 1 mg two or three times daily, gradually increasing as needed.
- Maximum Dose: 5 mg/day for children aged 7-12 years; 20 mg/day for adolescents aged 13-17 years.
- Pediatric Endocrinology Specialist: Should be involved in the management of children and adolescents receiving bromocriptine.
Special Cases:
- Elderly Patients: Start with a lower dose and titrate cautiously, considering age-related changes in organ function.
- Patients with Renal Impairment: Dose adjustment may be necessary but no specific guidelines are available; careful monitoring is recommended.
- Patients with Hepatic Dysfunction: Dose adjustment is likely needed due to reduced metabolism; close monitoring is essential.
- Patients with Comorbid Conditions: Individualized dosing based on the specific comorbidity.
Clinical Use Cases
Bromocriptine’s dosage in these settings would generally follow the standard dosage guidelines, with adjustments as needed based on patient response and tolerance:
- Intubation: Not specifically indicated.
- Surgical Procedures: No specific dosing adjustments unless related to existing conditions treated with bromocriptine.
- Mechanical Ventilation: Not specifically indicated.
- Intensive Care Unit (ICU) Use: No specific dosing adjustments unless related to existing conditions treated with bromocriptine.
- Emergency Situations: Not typically used in emergency situations unless for managing complications related to conditions treated with bromocriptine.
Dosage Adjustments
Dose adjustments may be necessary based on:
- Renal/Hepatic dysfunction
- Comorbidities
- Concomitant medications
- Individual patient response and tolerance
Side Effects
Common Side Effects:
- Nausea
- Vomiting
- Dizziness
- Headache
- Constipation
- Fatigue
- Nasal congestion
Rare but Serious Side Effects:
- Seizures
- Stroke
- Heart attack
- Psychosis
- Pulmonary fibrosis
- Pleural effusion
- Pericardial effusion
- Retroperitoneal fibrosis
Long-Term Effects:
- Valvular heart disease (with high doses)
- Impulse control disorders (rare)
Adverse Drug Reactions (ADR):
- Hypotension (especially orthostatic hypotension)
- Hallucinations/delusions
- Sudden sleep onset
Contraindications
- Hypersensitivity to bromocriptine or ergot alkaloids.
- Uncontrolled hypertension.
- Hypertensive disorders of pregnancy (pre-eclampsia, eclampsia).
- Postpartum hypertension.
Drug Interactions
- Dopamine antagonists (e.g., antipsychotics): Reduced effectiveness of bromocriptine.
- Erythromycin, clarithromycin (macrolide antibiotics): Increased bromocriptine levels.
- Antifungal azoles (e.g., ketoconazole): Increased bromocriptine levels.
- Alcohol: Increased risk of side effects.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: Not established. Use with caution. Discontinue if pregnancy is detected and desired.
- Fetal Risks: Potential for fetal harm, but data are limited.
- Breastfeeding: Bromocriptine suppresses lactation. Not recommended while breastfeeding if lactation is desired.
Drug Profile Summary
- Mechanism of Action: Dopamine D2 receptor agonist.
- Side Effects: Nausea, vomiting, dizziness, headache, constipation. Serious side effects include seizures, stroke, cardiac events.
- Contraindications: Hypersensitivity to bromocriptine or ergot alkaloids, uncontrolled hypertension, hypertensive disorders of pregnancy.
- Drug Interactions: Dopamine antagonists, macrolide antibiotics, antifungal azoles, alcohol.
- Pregnancy & Breastfeeding: Use with caution during pregnancy; contraindicated if breastfeeding is desired.
- Dosage: Varies by condition; initial dose typically 1.25-2.5 mg/day, titrated upward as needed.
- Monitoring Parameters: Blood pressure, prolactin levels, growth hormone levels (for acromegaly), and Parkinsonian symptoms.
Popular Combinations
- Levodopa/carbidopa (for Parkinson’s disease): Bromocriptine can be used as adjunctive therapy.
Precautions
- General Precautions: Monitor blood pressure, especially during initial dose titration. Assess for history of psychiatric illness.
- Specific Populations: Use cautiously in elderly patients and patients with renal or hepatic impairment.
- Pregnant Women: Avoid if possible.
- Breastfeeding Mothers: Contraindicated if breastfeeding is desired.
- Children & Elderly: Careful dosing and monitoring.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Bromocriptine?
A: The starting dose is typically 1.25-2.5 mg once daily, preferably with food at bedtime. Dosage is titrated based on patient response and tolerance, with maximum daily doses varying depending on the indication.
Q2: What are the most common side effects of Bromocriptine?
A: Nausea, vomiting, dizziness, headache, and constipation are common side effects.
Q3: Can Bromocriptine be used during pregnancy?
A: Bromocriptine should be used with caution during pregnancy and discontinued if pregnancy occurs and is desired, as its safety has not been fully established.
Q4: How does Bromocriptine work in Parkinson’s disease?
A: It activates dopamine receptors in the brain, mimicking the effects of dopamine, which is deficient in Parkinson’s disease.
A: Serious side effects include hallucinations, confusion, chest pain, shortness of breath, seizures, and signs of stroke or heart attack.
Q6: Can Bromocriptine be used to stop lactation?
A: Yes, bromocriptine can suppress postpartum lactation for medical reasons.
Q7: Does Bromocriptine interact with other medications?
A: Yes, it can interact with drugs such as dopamine antagonists, macrolide antibiotics, antifungal azoles, and alcohol.
Q8: Are there any dietary restrictions while taking Bromocriptine?
A: Alcohol should be avoided or limited while taking bromocriptine. It’s generally recommended to take bromocriptine with food to enhance absorption and reduce gastrointestinal side effects.
Q9: How should Bromocriptine be taken?
A: Bromocriptine should be taken orally with food, usually with the evening meal or at bedtime.
Q10: What should I do if I miss a dose of Bromocriptine?
A: Take the missed dose as soon as you remember, unless it is close to the time for your next dose. Do not double the dose to catch up.
